The problem to which this invention is directed is the blinding spray of water that is generated by large, fast moving vehicles, such as large trucks, and which spray presents a serious driving hazard to adjacent and following vehicles. Depending upon the density of the water layer on the roadway, this spray, at times, may become so intense and heavy and its dispersement such that it is thrown onto the windshields of following vehicles in a sufficient density that driving visibility may, at times, be reduced to nearly zero. Similarly, spray is thrown laterally of the wheels of a truck-type vehicle, particularly those of the tandem or dual tandem drive or trailer wheel, and a similar problem is developed with respect to passing vehicles or vehicles travelling in an adjacent lane. The wheels of trucks are of a sufficient vertical extent that water is thrown laterally from the top of those wheels and is thus essentially coincident with the height of passenger car windshields and accordingly produce a serious hazard in the form of greatly reduced visibility, particularly as to passenger vehicles.
This problem has been previously recognized and attempts have been made to provide a solution to control that spray and its dispersement. An example of a combination of side guard and rear mud flap or splash guard devices is illustrated in U.S. Pat. No. 3,721,459 granted to H. L. Lea on Mar. 20, 1973. That patent illustrates the basic combination of a vertically suspended mud guard which extends transversely with respect to the vehicle and is disposed a distance rearwardly of the vehicle wheels. Also, that patent discloses use of a side guard which comprises an elongated panel supported at the side of the vehicle and extending longitudinally with respect thereto. This panel is of a vertical height to extend downwardly from the trailer body and project slightly below the top portion of the vehicle wheels. The length is of an extent such that it begins a distance forwardly of the wheels and terminates rearwardly and may cooperatively engage with the transverse mud flap to form a closed upper chamber between those two elements and the trailer body. While the device as shown in U.S. Pat. No. 3,721,459 achieved a certain degree of success in its general objectives, that structure has not proven to be as fully satisfactory and effective as is desired. One of the problems of such a mud flap and side guard system is that the mud flap comprises a flat surfaced sheet of material that is flexible for performance reasons and because of manufacturing expedience, and comprises a smooth surface facing the rear wheels of the vehicle. The spary that is generated comprises water droplets and a fine mist that is thrown against this smooth surface and, as a partial consequence of air flow, will remain entrained in that air flow and be dispersed laterally with respect to the flap as well as having a portion thereof collected and directed downwardly to drain off the bottom of the flap and fall to the roadway.
In view of the general deficiencies and limitations of the spray system and splash guard as shown in U.S. Pat. No. 3,721,459, attempts have been made to improve at least the splash guards to reduce the airborne flow of water droplets and spray by attempting to collect the droplets and spray mist on the surface of the splash guard and direct such collected water, in a sheet form, downwardly and transversely across the guard where it will be discharged toward the surface of the roadway. An example of such an attempt is illustrated in U.S. Pat. No. 2,714,015 granted to C. E. Sherman on July 26, 1955. That patent illustrates a guard which has integrally formed on a front surface thereof, a plurality of upstanding ribs disposed in angled relationship and in combination with vertically extending ribs at each side of the guard. The objective of this arrangement of ribs was to collect the water that is thrown against the surface of the guard in the form of either relatively large droplets or a spray mist and, with that water which is then formed as a sheet or thin film of water, to direct its flow transversely of the guard. With the ribs oriented in a downwardly inclined relationship to the center of the guard and from each side as disclosed in that patent, the water will be caused to flow toward the center of the guard where it will then flow downwardly and discharge from the bottom edge. In the cas of a single wheel, that water was then caused to flow downwardly and deposited or discharged directly in the rear of a single wheel type axle. In the cas of a dual wheeled axle, the water would then have been deposited and discharged at a point which was aligned with the space between the two wheels.
Another example of a splash guard designed to control the flow of water that is collected on the surface of the guard is illustrated in U.S. Pat. No. 3,929,352 issued to Knut Arenhold on Dec. 30, 1975. That patent illustrates a guard having a vertically extending flange along one side and a plurality of upstanding ribs extending transversely from that side flange completely across the guard and terminating at the opposite edge which is not provided with a vertical flange. These ribes were intended to perform the function of directing and channelling water flow transversely across the entire width of a guard and, to enhance their performance, these ribs were arcuately curved to better enable them to retain the water and perform this channelling function. A disadvantage of this arrangement is that in the case of a dual wheel or tandem wheel arrangement, the width of the guard is of such an extent that the relatively small heighth ribs are incapable of retaining the water for directing its complete flow across the entire splash guard.
A further example of rib structures formed on splash guards and designed to achieve the same general objectives of the two previously cited U.S. patents is that disclosed in U.S. Pat. No. 3,198,545 granted to H. R. McDaniel on Aug. 3, 1965. That splash guard is constructed with an arcuate configuration to conform generally to the curvature of the vehicle wheel, and thus, the surface is disposed at a constant distance relative to the wheel surface. Additionally, the guard is provided on its forwardly facing surface adjacent to the wheel with a plurality of complex rib elements which have a function of attempting to collect water spray that is thrown upwardly by the wheel and to direct or channel the water that is thus collected on the surface of the guard in a downward direction where it may be discharged to the roadway. Again, this structure is of the same general type as that shown in the two previously noted U.S. patents wherein the only water collecting elements are the flow directing ribs, otherwise, the face of the guard is of a generally smooth nature and as a consequence, water droplets or spray thrown against the surface have a substantial tendency to rebound and are thus not collected on that surface. A structure designed to obviate that disadvantage is illustrated in United Kingdom Patent Application Ser. No. GB 2004823 filed Oct. 9, 1978. The structure shown in that patent application comprises a guard having a surface formed with a series of recesses or channels with the openings thereto designed to restrict outflow of water. Consequently, water droplets thrown into the recess or a spray mist that drifts into those recesses will be more likely retained in the channels and then caused to flow downwardly and be discharged from the bottom of the guard toward the roadway.
This problem associated with the generation of entrained water droplets and a fine mist as a consequence of the high speed of revolution of the vehicle wheels was further recognized in U.S. Pat. No. 3,899,192 granted to Walter W. Reddaway on Aug. 12, 1975. In this patent, W. W. Reddaway proposed a solution to this entrained spray problem in the form of splash guards and surface treatments of the body of the tractor and trailer comprising sheets of material having a surface provided with a multiplicity of filamentary-type fingers. In general, that surface may be characterized as an artificial turf in which those filamentary fingers that can be advantageously and economically formed from suitable plastic materials are extremely flexible and disposed in a random and sometimes intertwined relationship. The function of that surface is to receive the air entrained water and to collect that water that should impinge upon the surface of the guard. The collection efficiency of this guard is based on the concept that the multiplicity of flexible and intertwined filamentary fingers will permit penetration of the water droplets as well as a mist type spray and as a consequence of its impedance to air flow, will result in those particles of water being collected on the surface of the guard at the base of the filaments or within the interstices of adjacent filaments. Water that is collected may then flow downwardly and be discharged from the bottom edge of the guard.
Further recognition of this significant problem of collecting the water on the surface of a guard is demonstrated in British Pat. No. 1,101,143 which was filed Jan. 20, 1965. The structure proposed in that patent comprised a sheet form panel having vertically extending flanges at each side and a plurality of fingers or projections which extend outwardly from the surface. These projections which are a finger-like conical configuration are designed and dimensioned such that each conical projection is relatively spaced to all other adjacent fingers by a distance which is at least of the order of the base diameter of the projection. Thus, each of the fingers is relatively independent with respect to the others and a surface remains on the face of the guard panel for substantially uninhibited flow of collected water downwardly over that surface. With these fingers thus spaced, there is not sufficient impedance to flow to result in any directional control as to the water flow across the face of the panel, and consequently, water that is collected will generally flow downwardly and be discharged from the bottom edge of the panel. Side flanges are also provided with this guard to minimize lateral outward flow of any water that is collected on the panel and may be induced by air currents.
The structures disclosed in the several patents noted in the preceding paragraphs demonstrate the underlying and basic problems associated with the air entrained water droplets and mist generated by the vehicle wheels. As previously noted, this problem is control of not only the water droplets, but also the relatively fine mist that is generated and which has a greater tendency to remain entrained in the air and be carried along with that air and remain airborne. These patents clearly indicate that the previously attempted solutions were not only a mechanism for collection of the water that is entrained in the air flow generated by the revolving vehicle wheels, but a directive control as to the flow of that collected water to reduce its likelihood of again becoming airborne and continuing to produce the hazardous visibility problem to adjacent and following vehicles with respect to any particular automotive vehicle. However, none of these prior attempts to solve the problem indicated any combination of techniques and the effectiveness of the prior art splash guards has been less than desired.